BB.Caching.Tests.Hashing.ConsistentHashRingTests.NodeWeightVariesTest C# (CSharp) Метод

        public void NodeWeightVariesTest()
        {
            const long ITERATIONS = 100000;
            const int REPLICATIONS = 128;
            var nodes = new Dictionary<string, int>
                {
                    { "node1", 1 },
                    { "node2", 2 },
                    { "node3", 1 },
                    { "node4", 4 },
                    { "node5", 2 }
                };

            var ring = new BB.Caching.Hashing.ConsistentHashRing<string>();
            ring.Init(nodes, REPLICATIONS);

            var counts = new Dictionary<string, long>(
                ring.GetAvailableNodes().ToDictionary(n => n, n => 0L));

            var random = new Random();
            for (int i = 0; i < ITERATIONS; i++)
            {
                string s = Convert.ToBase64String(
                    Encoding.UTF8.GetBytes(random.Next(10000000, 1000000000).ToString(CultureInfo.InvariantCulture)));
                counts[ring.GetNode(s)] += 1;
            }

            float perUnit = (float)ITERATIONS / nodes.Sum(x => x.Value);

            foreach (var kvp in counts.OrderBy(k => k.Key))
            {
                Console.WriteLine("{0}: {1:#,##0} (target {2:#,##0})", kvp.Key, kvp.Value, nodes[kvp.Key] * perUnit);
            }

            double singleWeightExpectedValue = (double)ITERATIONS / nodes.Values.Sum();
            double allowedError = singleWeightExpectedValue * 0.20;

            foreach (var kvp in counts.OrderBy(k => k.Key))
            {
                Assert.True((nodes[kvp.Key] * singleWeightExpectedValue) - allowedError <= kvp.Value);
                Assert.True((nodes[kvp.Key] * singleWeightExpectedValue) + allowedError >= kvp.Value);
            }
        }